(1) Field of the Invention
The present invention generally relates to an apparatus and method for color range designation, and a computer readable medium for color range designation. The present invention more particularly relates to a color range designation apparatus, method and computer readable medium in which a color range for a portion of a display image is designated and the image with the designated color range is processed for displaying.
(2) Description of the Related Art
Conventionally, an image-compositing technique, such as chroma keying, is commonly used on image signals. An overlay image signal is selected instead of a background image signal whenever the overlay is not a particular preset hue, usually blue. Action shot in front of a blue screen can thereby appear on the top of the background signal. This image-compositing process is also called a blue-back process.
Before the above image-compositing process is performed, it is necessary to preset the background image signal to a particular color.
FIG. 1 shows a conventional image processing routine of the above type.
At a start of the conventional image processing routine of FIG. 1, step S1-1 performs a color designation processing. In the color designation processing, a particular color is designated for a portion of a display image. After the color designation processing is performed, step S1-2 performs a color range designation processing. In the color range designation processing, a range between a minimum color and a maximum color is designated for the portion of the display image based on the designation color. After the color range designation processing is performed, step S1-3 performs an image displaying processing. In the image displaying processing, the resulting image with the designated color range is displayed.
FIG. 2 shows a color designation processing in the conventional image processing routine.
In the color designation processing of FIG. 2, step S2-1 initializes a designation color for a portion of an original display image in response to a color designation request input by an operator. After the designation color is initialized at step S2-1, step S2-2 detects whether a designation color is input by the operator. The detection at step S2-2 is repeated until a designation color is input by the operator. After the designation color is input at step S2-2, step S2-3 stores the designation color in a memory. The color designation processing of FIG. 2 ends.
FIG. 3 shows a color range designation processing in the conventional image processing routine.
In the color range designation processing of FIG. 3, step S3-1 initializes a range between a minimum color and a maximum color for the portion of the original display image in response to the designation color input by the operator. After the color range is initialized at step S3-1, step S3-2 detects whether a designated color range (or a color difference with respect to the designation color) is input by the operator. The detection at step S3-2 is repeated until a designated color range (or a color difference) is input by the operator. After the designated color range (or the color difference) is input at step S3-2, step S3-3 calculates a minimum color of the designated color range from a difference of the designation color and the color difference, and calculates a maximum color of the designated color range from a sum of the designation color and the color difference. After the calculation at step S3-3 is performed, step S-4 stores the designated color range, including the minimum color and the maximum color, in the memory. The color range designation processing of FIG. 3 ends.
FIG. 4 shows an image displaying processing in the conventional image processing routine.
In the image displaying processing of FIG. 4, step S4-1 initializes the portion of the original display image in response to the designated color range determined by the color range designation processing. After the portion of the original display image is initialized at step S4-1, step S4-2 performs an image displaying of the image with the designated color range. In the image displaying, the image signal for the portion of the original display image is preset to the designation color, and the resulting image is displayed. After the resulting image is displayed at step S4-2, step S4-3 detects whether a change to the designation color is input by the operator. When a change to the designation color is input by the operator at step S4-3, the above step S4-2 is again performed. On the other hand, when no change is input by the operator, the image displaying processing of FIG. 4 ends.
FIG. 5 shows an operation of the conventional image processing routine.
As shown in FIG. 5, in the conventional image processing routine, a central color xe2x80x9cC0xe2x80x9d of a designated color range is determined by the designation color input by the operator, and a color difference xe2x80x9cdCxe2x80x9d with respect to the central color xe2x80x9cC0xe2x80x9d is determined by the designated color range input by the operator. A minimum color xe2x80x9cC1xe2x80x9d of the designated color range is automatically calculated from the central color C0 and the color difference xe2x80x9cdCxe2x80x9d in accordance with the equation C1=(C0xe2x88x92dC), and a maximum color xe2x80x9cC2xe2x80x9d of the designated color range is automatically calculated from the center color xe2x80x9cC0xe2x80x9d and the color difference xe2x80x9cdCxe2x80x9d in accordance with the equation C2=(C0+dC).
In the conventional image processing routine, the range between the minimum color and the maximum color is automatically determined from the central color and the color difference which are input by the operator. The resulting color range may not accord with a color range desired by the operator. It is difficult for the operator to easily designate a color range at a portion of a display image by a desired color range at the operator""s discretion.
An object of the present invention is to provide an improved color range designation apparatus and method in which the above-mentioned problems are eliminated.
Another object of the present invention is to provide a color range designation apparatus which allows an operator to easily designate a color range at a portion of a display image by a desired color range at the operator""s discretion.
Still another object of the present invention is to provide a color range designation method which allows an operator to easily designate a color range at a portion of a display image by a desired color range at the operator""s discretion.
A further object of the present invention is to provide a computer readable medium storing program code instructions which cause a processor to execute a color range designation that allows an operator to easily designate a color range at a portion of a display image by a desired color range at the operator""s discretion.
The above-mentioned objects of the present invention are achieved by a color range designation apparatus including: a color designation unit which inputs a designation pixel of a display image and determines a color of the designation pixel of the display image; and a color range data calculating unit which determines a range between a minimum color and a maximum color for the input designation pixel based on the color determined by the color designation unit.
The above-mentioned objects of the present invention are achieved by a color range designation method including the steps of: determining a color of a pixel of a display image by an input designation pixel; and determining a range between a minimum color and a maximum color for the input designation pixel based on the determined color.
The above-mentioned objects of the present invention are achieved by a computer readable medium storing program code instructions which cause a processor to execute a color range designation, including a program code device which causes the processor to determine a color of a designation pixel of a display image by an input designation color; and a program code device which causes the processor to determine a range between a minimum color and a maximum color for the input designation pixel based on the determined color.
In the color range designation apparatus and method of a preferred embodiment of the present invention, the color range data calculating unit determines a range between a minimum color and a maximum color for a pixel of a display image based on the designation pixel input by the operator. The color range designation apparatus allows the operator to easily designate a color range at the designation pixel of the display image by a desired color range at the operator""s discretion.
In the color range designation apparatus and method of the preferred embodiment, the color designation unit inputs an arbitrary one of pixels of the display image as the designation pixel. The color range designation apparatus allows the operator to easily designate a color range at the arbitrary one of pixels of the display image by a desired color range at the operator""s discretion.
In the color range designation apparatus and method of the preferred embodiment, the color designation unit sequentially inputs a number of arbitrary pixels among pixels of the display image as the designation pixel. The color range designation apparatus allows the operator to easily designate a color range at each of the arbitrary pixels of the display image by a desired color range at the operator""s discretion.
In the color range designation apparatus and method of the preferred embodiment, the color designation unit inputs a designation range of the display image, so that a number of pixels contained in the designation range are sequentially input as the designation pixel. The color range designation apparatus allows the operator to easily designate a color range at each of the arbitrary pixels of the display image by a desired color range at the operator""s discretion.
In the color range designation apparatus and method of the preferred embodiment, when a different designation color, input by the color designation unit for the designation pixel, falls outside the stored color range, the color range data calculating unit determines a range between a minimum color and a maximum color for the designation pixel based on the different designation color, so that the stored color range is renewed by the determined color range. The color range designation apparatus allows the operator to easily designate a color range at the designation pixel of the display image by a desired color range at the operator""s discretion.